The present invention relates to an electric machine such as a motor or generator of the induction type.
A motor is an electromechanical device which converts electrical energy, delivered in the form of voltages or currents, into mechanical energy that is represented as rotational movement. One common type of motor consists of two major elements, a stator and a rotor. The stator typically includes a wire coil having a number of windings. The rotor typically includes permanent magnets. The rotor and stator are mechanically arranged such that the rotor can move freely with respect to the fixed stator. Electromagnetic interaction between the stator and rotor then causes the rotor to move for each polarity change in the stator windings. Other types of electric machines such as generators may be constructed in a similar fashion.
In one type of motor, the stator is formed by laminating a number of disks formed of a ferrous material to provide a cylindrical stator housing. The core disks have formed therein tabs or tines that provide a structure around which are wrapped bare copper wire strands to form the windings. The stator housing provides a coaxial located open space into which is inserted the rotor assembly. The rotor assembly typically is made from a number of electromagnets spaced about a shaft. Typically, the magnets are contained or held with the shaft by an outer sleeve. The rotor assembly is rotatably supported mechanically within the stator housing by low friction bearings.